1966 SWB Step Rear Brake ID

[Casey66]

Just finished up replacing rotors, calipers, lines etc on the front brakes which a PO had upgraded to 70's era 5-lug disks. Got parts for a '77 and they worked just fine.

Now I'm getting started on the drums in the rear which look like they've also been swapped at some point to 5-lugs. I don't know if the PO used parts from the same source as the front or not, so I'm looking for advice on what parts I need to be looking for to do a rebuild on the hardware.

The markings on the front of the drums are:
3989541
MAX DIA 11.09

A search for that number pulls up an eBay listing for 67-72 CHEVY TRUCK NOS Rear Brake Drums 3989541. Since that's the only result, besides a posting here about mismatching drums on a '71, I wanted to see if anyone has any further info on these.

Here are some pictures:


5-lug drum on rear-end.


Markings on 5-lug drum on rear-end, "3989541". Also has marked, "MAX DIA 11.09"


5-lug drum heat side heat sinks on rear-end.


Inner plate on rear drums.


Upper inner plate on rear drums.


Lower inner plate on rear drums.


Brake pads in rear drums.


Inner hardware on rear drums (1).


Inner hardware on rear drums (2).

Thanks.

[aggie91]

Those are just standard 2" rear drum brakes. I've done this a number of times. Most of if not all of the parts are the same for many years.

I used 1977 c-10 11" x 2" rear drum brakes for the parts. Part numbers from Rock Auto.

Drums: RAYBESTOS 2065R {#102065, 2065, F2065} Professional Grade; Outside Diameter 13.64" / 5 Bolts / Finned, Rear; w/ 11" X 2" Brakes

Shoes: RAYBESTOS 449PG {#449NR, 449RR} Professional Grade; Organic; 11.00 X 2.00, Rear; w/ 11" X 2" Brakes

Wheel Cylinders: RAYBESTOS WC37080 {#2037080} Professional Grade, Rear; w/ 11" X 2" Brakes

Hardware Kit: CARLSON H7046 Drum All-In-One Kit, Rear; 473
OR: CARLSON H2324 Pro Kit, Rear; 473

Pretty straight forward.

[Casey66]

Excellent. Thanks aggie91 for the info. That's going to make it a lot easier.